/Engine/Source/Runtime/GeometryCore/Public/VertexConnectedComponents.h
Map arbitrary set IDs to indices from 0 to k-1 (if there are k components)
template<typename TriangleMeshType> [TMap](API\Runtime\Core\Containers\TMap)< int32, int32 > MakeComponentMap ( const TriangleMeshType & Mesh, int32 KeepSizeThreshold )